As is known the so-called BMA process for the production of hydrogen cyanide or hydrocyanic acid starts from methane and ammonia and operates in the absence of oxygen or air.
The reaction is carried out in suspended reaction tubes made of sintered aluminum oxide which are coated internally with a platinum catalyst.
Since the reaction proceeds endothermically the reaction tubes are heated and thereby there are maintained reaction temperatures of around 1300.degree. C. In order to avoid the occurrence of the reverse reaction the hydrogen cyanide containing gaseous mixture must be quickly cooled to temperatures below 400.degree. to 300.degree. C. This takes place in a water cooled chamber made of aluminum in the top of the furnace itself, see Ullmann, Enzyklopadie der technischen Chemie, 4th edition Vol. 9, pages 657-660, especially page 659; Dechema, Monograph (1959) Vol. 33 pages 28 to 46 and also German Pat. No. 959,364 and related but not identical Endter U.S. Pat. No. 2,987,382.
Since the reaction proceeds endothermically there is needed besides the synthesis gas a large amount of hot gas which makes the BMA process directly dependent on a supply of methane or natural gas. Therefore it is not suited for every situation.
As is described in German OS 2913925 and related Voigt U.S. application Ser. No. 133,358 filed Mar. 24, 1980 and now Pat. No. 4,289,741 this disadvantage is eliminated by the use of liquified gases as alternative sources of carbon.
It would be particularly favorable if besides easily transportable and storable carbon compounds there could be employed carbon compounds which produce a residual gas in the reaction with ammonia whose heat value is sufficient to supply the largest part of the energy needed for the reaction.